Method and device for transferring data over GPRS network

ABSTRACT

A method and device according to the present invention reorders Logical Link Control (LLC) Packet Data Units (PDUs) when user data is transferred over the radio interface between a Mobile Station (MS) and a packet data network. An objection of the present invention is to provide a method and system for transferring user data over a network ensuring the best quality of service characteristics.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to transferring data over a radiointerface in General Packet Radio System (GPRS) networks.

BACKGROUND OF THE INVENTION

[0002] In wireless telecommunication systems information is transferredover the radio interface between a transmitting and/or receivingcommunication device and a communication network. In General PacketRadio System (GPRS) networks, such as GPRS, Enhanced GRPS (EGPRS) andGSM Enhanced Data rate for Global Evolution (EDGE) Radio Access Network(GERAN) efforts has been made to improve the quality of the datatransfer and thus the quality of service (QoS). The term GPRS alsorelates to EGPRS, GERAN and other enhancements of the GPRS in thepresent application.

[0003] A mobile station (MS), a base station sub-system (BSS) comprisinga base transceiver station (BTS) and a base station controller (BSC)including a Packet Control Unit (PCU), and a serving GPRS support node(SGSN) are the main components of the GPRS architecture forcommunicating between a terminal device and the GPRS network. A gatewayGPRS support node (GGSN) enables data transfer between the GPRS networkand external data networks, such as an Internet. One or more GGSNs areconnected to a SGSN via Internet Protocol (IP) based GPRS backbonenetwork. When the MS communicates with external data networks, the GGSNoperates as an IP router between a MS and the external network. Packetdata channels (PDCH) are used as physical channels for the packet datatransfer in the GPRS. To transfer user data, i.e. other data notproduced by the GPRS protocols, a Packet Data Protocol (PDP) context isgenerated. All messages including PDP context messages are transferredusing a Temporary Block Flow (TBF) between a MS and GPRS network.

[0004] The Logical Link Control (LLC) protocol is used to transfer databetween a MS and a SGSN in the GPRS network. The technicalspecifications of the LLC layer protocol to be used for Packet DataTransfer (PDT) between a MS and SGSN are defined in the document 3GPP TS44 064 V 4.3.0 (2002-03) [1]. The LLC layer is independent of theunderlying radio interface protocol. The LLC protocol layer consists ofLogical Link Management Entities (LLME), Logical Link Entities (LLE) anda multiplex procedure. A LLE is the LLC layer protocol state machinecontrolling one logical link connection.

[0005] The LLC layer operates above a Radio Link Control (RLC) layer onthe MS side and above a Base Station Sub-system GPRS Protocol (BSSGP)layer on the SGSN side. Above the LLC layer is a SubNetwork DependentConvergence (SNDC) protocol layer, that controls the transfer of userdata Network layer Packet Data Units (N-PDU) between a MS and SGSN. Alsoabove the LLC layer locates a GPRS Mobility Management (GMM) protocollayer, that uses the services of the LLC layer to transfer messagesbetween a MS and a SGSN.

[0006] A MAC (Media Access Control) protocol layer locates under a RLClayer on the MS side. It defines the procedures that enable multiple MSsto share a common radio interface and it allows a MS to use severalphysical channels in parallel on the MS side of the GPRS network. TheMAC also provides the arbitration between multiple MSs simultaneouslyattempting to access a radio interface.

[0007] A RLC/MAC layer protocol of the GPRS is described in the document3GPP TS 44 060 V4.5.0 (2002-02) [2]. A R-LC/MAC block is a protocol dataunit exchanged between RLC/MAC entities, and a RLC/MAC control block isa part of a RLC/MAC block carrying a control message between RLC/MACentities or RLC data block is a part of a RLC/MAC block carrying userdata or signalling data of upper layers. The RLC layer defines theprocedures for segmentation and reassembly of LLC PDUs into RLC/MACblocks and the RLC layer provides also link adapatation. The RLC/MAC isresponsible for transmitting LLC PDUs over the radio interface using aTemporary Block Flow (TBF), which is a physical radio connectionsupporting the unidirectional transfer of LLC PDUs between a MS and thenetwork. A LLC PDU contains user data or GPRS protocol relatedsignalling messages, such as a GMM signalling message (GMM/SM). A MS mayhave an uplink TBF (UL TBF), a downlink TBF (DL TBF) or an uplink anddownlink TBF established at any time. When a transfer mode of LLC PDUsterminates, in either uplink or downlink direction, the correspondingTBF is released and the MS returns to packet idle mode. When a transfermode of LLC PDUs terminates but there exists an on-going LLC PDUtransfer to the other direction, the MS stays in transfer mode.

[0008] One TBF may carry RLC data blocks only in one RLC mode at a time.This means that when transferring in-sequence LLC PDUs utilizingdifferent RLC modes (ACK or UNACK), a previous TBF has to be releasedand a new TBF has to be established for a new RLC mode. The LLC isintended for use with both acknowledged (LLC ACK) and unacknowledged(LLC UNACK) data transfer and the RLC/MAC supports both the RLC ACK modeand RLC UNACK mode. The LLC modes and the RLC modes are independent fromeach other. In the LLC ACK mode the LLC provides a reliable service within-order delivery but in the LLC UNACK mode the LLC does not guaranteein-order delivery. In RLC ACK mode RLC uses retransmissions to guaranteeerror-free transmission and in RLC UNACK mode retransmissions are notused. In both modes RLC/MAC specification says that upper layer PDUsshall be delivered in the order they are received from upper layers. InRLC UNACK mode one lost RLC data block may result in discarding of thewhole LLC PDU at the receiving side. In the RLS ACK mode Backward ErrorCorrection (BEC) procedures enable the selective retransmission ofunsuccessfully delivered RLC/MAC blocks.

[0009] According to the Technical Specifications 3GPP TS 44 064 V 4.3.0[1] the RLC shall deliver LLC PDUs received from the upper layers in thesame order as they were received from the upper layers. This means thatLLC PDUs are delivered in the same order as received from the upperlayers (i.e. LLC layer), regardless of the fact that some LLC PDUs mayhave e.g. higher priority than other LLC PDUs. This is a big problemwhen transferring e.g. real-time or other delay sensitive data over theradio interface, because also this data, despite of its high priority,have to hold on the transmitting queue of in-order delivary. This mayimpair the QoS of the application.

[0010] The LLC allows data transfer with different service criteria,such that high-priority data transfers may take precedence overlower-priority data transfers to the same MS. A LLC PDU has certain QoScharacteristics concerning the RLC mode, priority, throughput, etc. Whenstreaming data or otherwise delay sensitive data, such as speech, istransferred over the GPRS network, it should be delivered before e.g.best effort data, such as FTP (File Transfer Protocol) data or websurfing, to ensure the QoS. Otherwise the service suffers bad quality.Recently an intrest towards transferring delay sensitive data over theGPRS network is rising.

[0011] An example is now provided to describe the current state of theprior art. Assume that the RLC/MAC of the MS first receives three shortLLC PDUs from a delay sensitive application that needs to be transmittedusing the RLC UNACK mode. After this the RLC/MAC receives two long, e.g.1500 octet each, LLC PDUs containing FTP data that needs to betransmitted using the RLC ACK mode. Then after this the RLC/MAC againreceives three short LLC PDUs from the delay sensitive application thatneeds to be transmitted using the RLC UNACK mode. When changing atransfer mode from the RLC UNACK mode to the RLC ACK mode, first anexisting TBF is released, then a new TBF is established and then FTPtraffic LLC PDUs are transferred in RLC data blocks. After this atransfer mode is changed from the RLC ACK mode to the RLC UNACK modeagain by releasing existing TBF and establishing new TBF, and then atransfer of data packets of the delay sensitive application maycontinue. A time needed to transfer FTP traffic LLC PDUs in the RLC datablock depends on the number of assigned uplink PDCHs. The elapsed timealso depends on a channel coding scheme used to transfer RLC data blocksover the radio inferface and how frequently the TBF is assigned sendingpermissions. In this example, a transfer of two 1500 octet long LLC PDUsin the RLC ACK mode between the delay sensitive data packets may takeseveral seconds. The gap of several seconds will result in that delaysensitive applications will substantially suffer from the FTP transfer.

[0012] The gap of several seconds will result in that a transfer of realtime LLC PDUs of applications using streaming or otherwise delaysensitive data will be blocked by a transfer of non-real time LLC PDUsof applications using FTP or other best effort data according to thecurrent specifications. In case of a speech application the quality ofthe conversation becomes unacceptable. From the foregoing it followsthat the current GPRS network is unable to transfer delay sensitive dataover the radio interface.

[0013] There are significant problems related to prior art to transferdelay sensitive data over the GPRS network. Grounds for the problems inprior art is the fact that a RLC/MAC does not interprete contents of aLLC PDU at all, and it only transfers a LLC PDU, such as received from aLLC, over a radio interface.

SUMMARY OF THE INVENTION

[0014] An objective of the present invention is to provide a method andsystem for transferring user data over a network ensuring the bestquality of service characteristics.

[0015] The objective of the present invention is fulfilled byprioritising a packed user data message delivery according to a datacontent of a message and by associating the Packet Data Protocol (PDP)context to the radio interface access points via which the packed datamessage is transferred over the network.

[0016] In accordance with the present invention there is provided amethod related to a mobile station for transferring user data in awireless packet data network, wherein the method comprises the steps of:

[0017] at a certain protocol layer, receiving a first packet datamessage from an upper protocol layer, which first packet data messagebelongs to a first packet data protocol (PDP) context characterised bycaertain first connection information,

[0018] at said certain protocol layer, receiving a second packet datamessage from an upper protocol layer, which second packet data messagebelongs to a second packet data protocol (PDP) context characterised bycertain second connection information,

[0019] reordering said first packet data message and said second packetdata message said certain protocol layer according to a relative urgencyof transmission of said first and second packet data protocol (PDP)contexts, and

[0020] delivering said first packet data message and said second packetdata message further from said certain protocol layer in reorderedorder.

[0021] In accordance with the present invention there is provided amobile station (MS) for transferring user data in a wireless packet datanetwork, the mobile station (MS) comprising a transceiver fortransmitting and receiving packet data messages, wherein the mobilestation (MS) comprises:

[0022] a controller configured to generate packet data protocol contextactivation messages for informing the network about the activation ofpacket data protocol (PDP) contexts for user data transmission, and

[0023] a layered transmission protocol arrangement comprising a certainprotocol layer entity as well as higher protocol layer entities, ofwhich said certain protocol layer entity is configured to receive packetdata messages belonging to different packet data protocol (PDP) contextsfrom at least one upper protocol layer, to reorder packet data messagesreceived from at least one upper protocol layer according to a relativeurgency of transmission of packet data protocol (PDP) contexts that thepacket data messages belong to, and to deliver packet data messagesfurther from said certain protocol layer in reordered order.

[0024] In accordance with the present invention there is provided amethod related to a network element of a wireless network fortransferring user data between a mobile station (MS) and a wirelesspacket data network, wherein the method comprising the steps of:

[0025] at a certain protocol layer, receiving a first packet datamessage from an upper protocol layer, which first packet data messagebelongs to a first packet data protocol (PDP) context characterised bycertain first connection information,

[0026] at said certain protocol layer, receiving a second packet datamessage from an upper protocol layer, which second packet data messagebelongs to a second packet data protocol (PDP) context characterised bycertain second connection information,

[0027] reordering said first packet data message and said second packetdata message at said certain protocol layer according to a relativeurgency of transmission of said first and second packet data protocol(PDP) contexts, and

[0028] delivering said first packet data message and said second datadata message further from said certain protocol layer in reorderedorder.

[0029] In accordance with the present invention there is provided anetwork element of a wireless network for transferring user data betweena mobile station (MS) and a wireless packet data network, whereinnetwork element comprises:

[0030] a controller configured to generate packet data protocol (PDP)context activation messages for informing the network about theactivation of packet data protocol (PDP) contexts for user datatransmission, and

[0031] a layered transmission protocol arrangement comprising a certainprotocol layer entity as well as higher protocol layer entities, ofwhich said certain protocol layer entity is configured to receive packetdata messages belonging to different packet data protocol (PDP) contextsfrom at least one upper protocol layer, to reorder packet data messagesreceived from at least one upper protocol layer according to a relativeurgency of transmission of packet data protocol (PDP) contexts that thepacket data messages belong to, and to deliver packet data messagesfurther from said certain protocol layer in reordered order.

[0032] Some embodiments of the invention are described in the dependentclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Next the present invention will be described in greater detailwith reference to exemplary embodiments in accordance with theaccompanying drawings, in which:

[0034]FIG. 1 illustrates a block diagram of a mobile station (MS)according to an embodiment of the present invention.

[0035]FIG. 2 illustrates a flow diagram of a method according to thepresent invention.

DETAILED DESCRIPTION

[0036] A preferred embodiment of the present invention is prioritisingof Logical Link Control (LLC) Packet Data Units (PDUs) when user data istransferred over the radio interface between the Mobile Station (MS) andthe GPRS network. According to the invention LLC PDUs are reorderedbased on their requirements.

[0037] According to one embodiment of the invention a Radio LinkControl/Media Access Control (RLC/MAC) is able to reorder LLC PDUsinside a RLC/MAC and a LLC associates a Packet Data Protocol (PDP)context to a LLC Service Access Point Indicator (SAPI) intelligently.The present invention enables a LLC PDU to be prioritised in RLC/MAC andthus it enables applications to receive the quality of service (QoS)they need. Based on the additional QoS information received along theLLC PDU, RLC/MAC unit is able to prioritise LLC PDUs according to theirurgency of transmission in relation to other LLC PDUs.

[0038] According to another embodiment of the invention LLC PDUs arereordered elsewhere than in a RLC/MAC.

[0039] In the following description reordering in a RLC/MAC is used asan example.

[0040]FIG. 1 shows a block diagram of an embodiment of wirelesscommunication system 3 comprising at least one mobile station (MS) 10, anetwork 50 and a radio link connection 40 according to the presentinvention. On the network side of the wireless communication system 3there is also illustrated in FIG. 1 a Serving General Packet RadioService (GPRS) Support Node (SGSN) 55 provided by a wireless networkoperator, at least one base station controller (BSC) 54 including aPacket Control Unit PCU and at least one base transceiver station (BTS)51 including antenna 53 to wirelessly communicate with the MS 10 overthe radio interface in accordance with a predetermined radio interfacespecifications. A BTS 51 and BSC 54 are included to a Base StationSub-system (BSS) 52. The radio interface 40 enables to transfer bothvoice and data traffic, including an Internet access and web browsing.At least one gateway GPRS support node (GGSN) 58, connected to a SGSN 55via IP-based GPRS backbone, provides a connection to external datanetworks 61. According to the present invention the radio interfacesupports, but is not limited to, General Packet Radio System (GPRS)networks, such as GPRS, Enhanced GRPS (EGPRS), GSM (Global System forMobile communications) Enhanced Data rate for Global Evolution (EDGE)Radio Access Network (GERAN) and any other enhancements of the GPRS orGSM or combinations thereof. The term GPRS relates to all those in thispresent application.

[0041] In FIG. 1 a MS 10 may be a handheld radiotelephone, such as acellular phone, a personal communicator or alike. The MS 10 typicallyincludes a microcontroller unit (MCU) 11 coupled to a display unit 12and a keyboard unit 13 for a user interface (as well as a microphone andspeaker). The MS 10 also contains a digital signal processor (DSP) 17 orequivalent, and a wireless tranceiver unit 18 including transmitter,receiver and antenna 19 functions. The MCU 11 is connected to a memory14 for storing an operation program, received packet data, packet datato be transmitted, and the like. In association with the memory 14 is abuffer unit 15 for storing packet data messages into a transfer queueand for delivering packet data messages from the buffer to provide anin-order delivery of packet data messages according to the presentinvention.

[0042] The memory 14 also includes a Read-Only Memory (ROM) which inassociation with the MCU 11 provides a Radio Link Control/Medium AccessControl (RLC/MAC) unit 11 a, a SubNetwork Dependent Convergence Protocol(SNDCP) unit 11 c for user data transfer, a GPRS Mobility Management(GMM) unit 11 d and a Logical Link Control (LCC) unit 11 b to store aprogram enabling the MCU 11 to execute software routines, layers andprotocols required to implement the methods according to the presentinvention. The SNDCP unit 11 c and GMM unit 11 c are locating on thesame protocol layer. On the network 50 side in association with the BSC54 are a RLC/MAC unit 54 a and a BSSGP unit 54 b, and in associationwith the SGSN 55 are a BSSGP unit 55 a, a LLC unit 55 b, a SNDCP unit 55c, and GMM unit 55 d. Functional operation of these units is alsocontrolled by software instructions from the network operator'spremises. The SNDCP unit 55 c and GMM unit 55 d are locating on the sameprotocol layer.

[0043] In the GPRS network a packet data message is always transferredvia a LLC layer which operates above RLC and BSSGP layers to providelogical links between a MS and its SGSN. Messages transferred via a LLClayer are called LLC packet data unit (LLC PDU) messages. Above a LLClayer is e.g. a SNDC protocol layer which controls the transfer of userdata between a MS and SGSN. A data link connection of a LLC layer toprovide services e.g. to the GMM and SNDC protocol layers is identifiedby a Service Access Point Identifier (SAPI) both on the SGSN and MSside. The SAPI is carried in the address field of the frame header ofeach LLC frame. LLC PDUs are segmented and reassembled into RLC/MACblocks defined by a RLC layer. A TBF allocated on one or more PDCHscomprises a number of RLC/MAC blocks carrying one or more LLC PDUs. ATBF is temporary and is maintained only for a duration of the datatransfer.

[0044] When LLC Packet Data Units (LLC PDU) are transferred between a MS10 and BSS 52 and between a BSS 52 and SGSN 55 a LLC Relay providesservices to the RLC layer protocol. An LLC layer connection isidentified via Service Access Points (SAP) in the LLC layer. In case theRLC/MAC unit 54 a of the network is located in the BSS 52, the LLC relayoperates above the RLC/MAC. In case RLC/MAC unit is located in the SGSN,the LLC operates directly above the RLC/MAC. According to specifications[1] the RLC/MAC may be located in the network in the BTS, BSC or SGSN.

[0045] A SAP Identifier (SAPI) is used to identify a SAP on the SGSNside of the LLC interface and on the MS side of the LLC interface. In aLLC frame a SAPI includes an address field which is part of a frameheader (LLC header). The SAPI identifies upper layer entity thatreceives a LLC PDU, e.g. a GMM, SMS, SNDCP. For example, if a SAPI isequal to 1 (SAPI=1), this LLC PDU goes to the GMM. A SAPI is also usedas an internal LLC information in order to be able to handle PDUs withappropriate QoS characteristics. For example, when a SNDCP PDU usingNSAPI (NSAPI is a PDP context ID) is received from a SNDCP, the PDU istransferred e.g. using the LLC SAPI=3 and during the PDP contextactivation procedure certain QoS characteristics have been associated tothe PDP context.

[0046]FIG. 2 shows a flow diagram of an embodiment of a method relatedto a mobile station (MS) for transferring user data in a wireless packetdata network according to the present invention. The present inventionimproves a way to transfer real-time (RT) and otherwise delay sensitivedata over radio interface between the MS and the SGSN enablingapplications to receive service they need.

[0047] In step 201 the MS 10 generates a protocol activation message forinforming the network to activate a packet data protocol (PDP) contextfor user data transmission. To do this, the GMM unit 11 d generates aGMM/SM message “Activate PDP Context Request” and moves it to the LLCunit 11 b to pack it to be a LLC PDU message. The LLC unit 11 bassociates a LLC PDU message to the LLC GMM SAPI and defines a LLC modeto be used to transfer the LLC PDU message. The LLC modes are a LLC ACKmode and LLC UNACK mode which are independent of a RLC mode. Then LLCunit 11 b moves the LLC PDU message to the RLC/MAC unit 11 a to transferit over the network.

[0048] Then the MS 10 in step 203 sends to the network “Activate PDPContext Request” message. The RLC/MAC unit 11 a transfers this LLC PDUmessage consisting a LLC header including a SAPI to the RLC/MAC unit 54a locating in the BSC 54 where it is transmitted to the SGSN 55according to step 204. LLC unit 55 b identifies the SAPI from the LLCheader of the LLC PDU message. Then the LLC unit 55 b moves a datacontent of the LLC PDU to the GMM/SM unit 55 d according to the SAPI.Next, the GMM/SM unit 55 d either accepts or rejects the request bytransmitting a message “Activate PDP Context Accept” (step 205) or“Activate PDP Context Reject” (step 207). If the GMM/SM unit 55 daccepts the PDP context activation, all information needed to route auser data is available to all GPRS network entities. E.g. a GGSN knowsthe IP address to be used and can route user data packets to the rightSGSN serving the MS (GGSN is unaware of LLC). In association withactivating PDP context QoS characteristics are also defined for the PDPcontext (and user data transferred using the PDP context).

[0049] When a PDP context is activated in step 207, the LLC unit 55 bassociates the PDP context to a LLC SAPI based on QoS requirements ofthe PDP context according to the Technical Specifications 3GPP TS 23.060V 3.12.0 “General Packet Radio Service (GPRS); Service description” [3].It says about multiplexing of N-PDUs from one or several NSAPIs onto oneLLC SAPI that NSAPIs which are multiplexed onto the same SAPI shall usethe same radio priority level, QoS traffic handling priority, andtraffic class. This means that if a MS has two active PDP contexts, thePDP context transferring delay sensitive data and the PDP contexttransfering best effort data can't be associated to the same SAPIaccording to specifications. Thus, different PDP contexts shall use adifferent LLC SAPI and similar PDP contexts may use the same LLC SAPI.However in case of two quite similar PDP contexts, they may also bedefined to use a different LLC SAPI in order to be able to reorder LLCPDUs belonging to different PDP contexts. An example: two streaming PDPcontexts are activated, one carries voice and the other carries video.Usually if a video gets stuck for a while, it doesn't matter as much asif there's a break in voice. Therefore by prioritising voice over videoin this case, we obtain better result.

[0050] When transferring user data a SNDCP unit 55 c becomes active instead of a GMM unit 55 d. In step 209 a SNDCP unit 55 c receives a userdata packet. Then it segments a user data packet and transfers it to theLLC unit 55 b. The user data packet carries a NSAPI identifier of thePDP context. A NSAPI is one way to identify data belonging to differentPDP context. Because a SNDCP and LLC share an internal interface, theLLC unit knows on the basis of the NSAPI to which LLC SAPI the user datapacket must be connected. After this the LLC unit 55 b packs the userdata packet to a LLC PDU message containing the user data a LLC headerand a frame check sequence (FCS). FCS is used to detect bit errors inthe frame header and user data field. In this phase the LLC unit 55 blabels the LLC PDU message with a LLC window number, on the basis onwhich a receiving LLC unit 11 b can process the LLC PDU messageproperly. The LLC unit 55 b then passes the LLC PDU message to theRLC/MAC unit 54 a. The LLC PDU message contains information how theRLC/MAC unit has to process it. This information includes e.g. a RLCmode, throughput and priority information. According to this informationRLC/MAC unit 54 a is able to transfer the LLC PDU over the radio inappropriate way. A new TBF may not have to be established in case therealready exists one.

[0051] Then in step 211 the RLC/MAC unit 54 a reads a LLC SAPI from theLLC header of each LLC PDU message containing user data packets andreorders certain LLC PDU messages on the basis of the LLC SAPI. Based onLLC PDU a RLC/MAC unit is able to read which LLC SAPI the LLC PDU uses.Based on the additional QoS information received along the LLC PDU,RLC/MAC unit is able to prioritise LLC PDUs not utilizing the same LLCSAPI. The RLC/MAC unit doesn't know what kind of QoS characteristics areused for a certain LLC SAPI, but the information is received along theLLC PDU. When a PDP context has been associated to a certain LLC SAPI,all LLC PDUs associated to this PDP context are routed via LLC layerusing this same LLC SAPI.

[0052] When RLC/MAC unit receives LLC PDU, the RLC/MAC checks if it hasalready buffered LLC PDUs (steps 211 and 217). In case there arebuffered LLC PDUs and the received and the buffered LLC PDUs utilizedifferent LLC SAPI or the same LLC SAPI but different LLC mode(ACK/UNACK), RLC/MAC is able to reorder the LLC PDUs according to theirQoS requirements (steps 215). The LLC PDU with higher QoS information istransmitted (steps 213 and 215) before the LLC PDU with lower QoSinformation (step 219).

[0053] An example:

[0054] A RLC/MAC buffer 15 situation in the beginning: (head) SAPI=7,SAPI=7, SAPI=7 (tail)

[0055] A new LLC PDU with LLC SAPI=3 is received. According to QoSreceived along the LLC PDUs, if QoS of LLC PDU using SAPI=3 is higherthan QoS of LLC PDUs using LLC SAPI=7, a RLC/MAC buffer looks like:

[0056] RLC/MAC buffer 15 situation: (head) SAPI=3, SAPI=7, SAPI=7,SAPI=7 (tail)

[0057] Otherwise if QoS of a LLC PDU using SAPI=3 is lower than QoS ofLLC PDUs using LLC SAPI=7, a RLC/MAC buffer looks like:

[0058] RLC/MAC buffer 15 situation: (head) SAPI=7, SAPI=7, SAPI=7,SAPI=3 (tail)

[0059] The RLC/MAC unit 54 a of the network indicates to the RLC/MACunit 11 a, and vice versa, if the RLC ACK mode or the RLC UNACK mode isto be used. When using RLC ACK mode the MS 10 can be sure that atransferred LLC PDU is received by the network 50. A transmittingRLC/MAC unit always tells a receiving RLC/MAC unit in association a TBFestablishment which RLC mode is used to transfer LLC PDUs.

[0060] Throughput of RT data should be ensured and NRT data should bebuffered in case there is RT data to be transmitted. An advantage ofreordering LLC PDUs compared to the FTP example described in thebackground section of prior art is that RT data is transmitted beforeNRT data and thus RLC mode doesn't have to be changed in the middle ofthe TBF (TBF release and establishments) in case RT dat and NRT data usedifferent RLC mode.

[0061] If during data transfer LLC PDU using different RLC mode than theone used with existing TBF is received, MS/PCU 10, 54 shall check if thesending of the LLC PDU may be delayed and possibly if LLC PDUs may bereorganized. Only after transferring LLC PDUs having higher priority,the LLC PDUs using different RLC mode shall be transmitted.

[0062] In case RLC/MAC unit 54 a has reorganized and delayed thetransmission of LLC PDU transmission not carrying high priority data,RLC/MAC unit shall be able to determine when it may transmit the delayedLLC PDUs not carrying high priority data. There are three alternativeways to detect an end of a high priority data transfer:

[0063] One alternative is that after sending the last LLC PDU carryinghigh priority data RLC/MAC unit 54 a starts transmitting LLC PDUs notcarrying high priority data. As soon as new high priority data isreceived, RLC/MAC unit finishes the ongoing transmission of LLC PDU notcarrying high priority data and after that continues transmission withLLC PDUs carrying high priority data. This alternative creates somedelay between two subsequent high priority data packets, depending onthe length and RLC mode of the LLC PDU not carrying high priority data.

[0064] Another solution to the problem is that after sending the lastLLC PDU carrying high priority data RLC/MAC unit 54 a starts a timerwith short timeout value (e.g. 100-200 ms). If the timer expires andRLC/MAC unit hasn't received new high priority data, RLC/MAC is allowedto start transmission of LLC PDUs not carrying high priority data.

[0065] A third alternative is that the RLC/MAC unit 54 a waits untilhigh priority frames in RLC/MAC buffer 15 have been transmitted. In caseRLC/MAC unit runs (temporarily) out of high priority data, RLC/MACstarts to transmit other LLC PDUs located in RLC buffer. If RLC receivesnew high priority data during transmission of low priority data, RLC/MACunit could interrupt transmission of the current LLC PDU by generatingLLC PDU border into RLC data block and continue transmitting LLC PDUscarrying high priority data in order to avoid delayes in high prioritydata transmission. A downside of this solution is that a fake LLC PDUborder might create confusion in LLC (however most likely LLC PDU CRC(FCS) checking would fail).

[0066] In the receiving end a SNDCP unit 11 c receives a LLC PDUcontaining user data packet. Then it segments a user data packet andtransfers it to the LLC unit 11 b. LLC PDUs are bufferred into thetransfer queue 15 in association with the memory 14. When a LLC unit 55b sends a LLC PDU to peer LLC unit 11 b via RLC/MAC, a LLC unit 11 breceiving the transmitted LLC PDU checks that it receives LLC PDUsin-sequence order, what is needed not to break the operation of the LLClayer. This checking is based on a window number inside a LLC header ofthe LLC PDU. The window number is also used to check if received LLC PDUis a dublicate or a new LLC PDU. The window number increments by one (1)every time when a new LLC PDU is transmitted from LLC unit 11 b to theRLC/MAC unit 11 a and thus LLC unit 11 b checks that the window numberof a received LLC PDU also increments in-sequence order (1, 2, 3, . . .). Each LLC SAPI has its own series of window numbers, i.e. LLC SAPI 1has window numbers (1, 2, 3, . . . ), LLC SAPI 2 (1, 2, 3, . . . ), . .. , LLC SAPI 5 (1, 2, 3, . . . ), etc. In case the window number of thereceived LLC PDU increments in-sequence order, the LLC PDU istransferred to the transfer queue buffer 15. If the window number of thereceived LLC PDU (e.g. 1) was smaller than that of the previous LLC PDU(e.g. 50), i.e. the in-sequence order in not valid, the received LLC PDUmay be discarded. The RLC/MAC unit 11 a only transfers the LLC PDUmessage and it doesn't concern the contents of the LLC PDU message.

[0067] The MS 10 may also propose a LLC SAPI to be used with the PDPcontext but in any case the SGSN 55 determines a used LLC SAPIeventually.

[0068] A feature according to a method of the present invention may beimplemented in a mobile station (MS) 10, in a Serving General PacketRadio Service (GPRS) Support Node (SGSN) 55, and in a Packet ControlUnit (PCU) containing network RLC/MAC 61 in association with a BaseStation Controller (BSC) 53 or a mobile switching center (MSC).

[0069] The invention is not restricted to the embodiments describedabove. While a preferred embodiment of the present invention isdisclosed herein for purposes of explanation, numerous changes,modifications, variations, substitutions and equivalents in whole or inpart should now be apparent to those skilled in art to which theinvention pertains. Substitutions of elements from one describedembodiment to another are also fully intended and contemplated.Accordingly, it is intended that the present invention be limited onlythe spirit and scope of the hereto appended claims.

What is claimed is:
 1. A method related to a mobile station fortransferring user data in a wireless packet data network over a radiointerface between the mobile station and a network element, wherein themethod comprises the steps of: at a certain protocol layer, receiving afirst packet data message from an upper protocol layer, which firstpacket data message belongs to a first packet data protocol (PDP)context characterised by certain first connection information, at saidcertain protocol layer, receiving a second packet data message from anupper protocol layer, which second packet data message belongs to asecond packet data protocol (PDP) context characterised by certainsecond connection information, reordering said first packet data messageand said second packet data message at said certain protocol layeraccording to a relative urgency of transmission of said first and secondpacket data protocol (PDP) contexts, and delivering said first packetdata message and said second packet data message further from saidcertain protocol layer in reordered order.
 2. A method according toclaim 1, wherein the steps of receiving the first packet data messageand receiving the second packet data message precede a step ofconfiguring comprising further steps of: generating packet data protocol(PDP) context activation messages for informing the network about theactivation of packet data protocol (PDP) contexts for user datatransmission, and transmitting packet data protocol (PDP) contextactivation messages to the network to associate the packet data protocol(PDP) contexts to the first packet data message and to the second packetdata message.
 3. A method according to claim 2, wherein the methodcomprises a step of requesting an uplink resource for transmitting saidpacket data protocol (PDP) context activation messages.
 4. A methodaccording to claim 3, wherein the method comprises a step of requestingan uplink Temporary Block Flow (TBF) for transmitting protocolactivation packet data unit (PDU) messages.
 5. A method according toclaim 4, wherein the step of receiving comprises a preliminary step ofchecking that said first packet data messages and said second packetdata messages are received in-sequence order according said connectioninformation of said first packet data message or said second packet datamessage.
 6. A method according to claim 5, wherein the first packet datamessage containing first user data belongs to first packet data protocol(PDP) context, and the second packet data message containing second userdata belongs to second packet data protocol (PDP) context.
 7. A methodaccording to claim 6, wherein said first and second user data comprisingurgency of transmission profile, wherein the urgency of transmissionprofile includes an additional quality of service (QoS) information ofthe user data, the first packet data message and the second packet datamessage are reordered according to the urgency of transmission profile,if the first connection information differs from the second connectioninformation, by first delivering the packet data unit message comprisinghigher urgency of transmission profile.
 8. A method according to claim7, wherein said first and second user data comprising urgency oftransmission profile, wherein the urgency of transmission profileincludes an additional quality of service (QoS) information of the userdata, the first packet data unit (PDU) message and the second packetdata unit (PDU) message are reordered according to the urgency oftransmission profile, if the first connection information is equal tothe second connection information, by first delivering the packet dataunit (PDU) message comprising higher urgency of transmission profileusing other connection information.
 9. A method according to claim 8,wherein the method comprises further steps: the step of reorderingfurther comprises buffering said second packet data messages into apacket data transfer queue for a period of time said first packet datamessage transfer is on-going, and the step of delivering furthercomprises delivering said second packet data messages after said firstpacket data message delivery is completed.
 10. A method according toclaim 9, wherein the wireless packet data network is comprised of aGeneral Packet Radio Service (GPRS) network, wherein said first packetdata messages and said second packet data messages are Logical LinkController (LLC) packet data unit (PDU) messages, and where the protocolactivation message activates a GPRS Mobility Management (GMM) unit toassociate the packet data protocol (PDP) context to said first packetdata messages and to said second packet data messages.
 11. A methodaccording to claim 10, wherein a Logical Link Controller (LLC) unitassigns a first Service Access Point Indicator (SAPI) of a GPRS MobilityManagement (GMM) unit to associate said first connection information ofsaid first packet data message, and a second Service Access PointIndicator (SAPI) of a GPRS Mobility Management (GMM) unit to associatesaid second connection information of said second packet data message;said first SAPI value being different than said second SAPI value.
 12. Amethod according to claim 11, wherein said first packet data message andsaid second packet data message are reordered according to said firstSAPI value and said second SAPI value.
 13. A method according to claim12, wherein a Radio Link Control/Medium Access Control (RLC/MAC) unitreorders said first packet data message and said second packet datamessage according to said first SAPI value and said second SAPI value.14. A method according to claim 13, wherein a Radio Link Control/MediumAccess Control (RLC/MAC) unit reads a used SAPI value of the LogicalLink Controller (LLC) packet data unit (PDU) message from the LLC PDUmessage.
 15. A method according to claim 14, wherein after sending thelast LLC PDU message carrying high priority urgency of transmissionprofile the Radio Link Control/Medium Access Control (RLC/MAC) unitinitiates transmitting LLC PDU messages not carrying high priorityurgency of transmission profile.
 16. A method according to claim 14,wherein after sending the last LLC PDU message carrying high priorityurgency of transmission profile the Radio Link Control/Medium AccessControl (RLC/MAC) unit starts a timer with a predetermined timeout valueand after said timeout value, said RLC/MAC unit initiates transmittingLLC PDU messages not carrying high priority urgency of transmissionprofile if said RLC/MAC unit has not received a new LLC PDU messagecarrying high priority urgency of transmission profile during saidpredetermined timeout value.
 17. A method according to claim 14, whereinduring transmitting LLC PDU messages not carrying high priority urgencyof transmission profile the Radio Link Control/Medium Access Control(RLC/MAC) unit interrupts said transmission if said RLC/MAC unitreceives a new LLC PDU message carrying high priority urgency oftransmission profile during said transmission, and said RLC/MAC unitinitiates transmitting said new LLC PDU message carrying high priorityurgency of transmission profile.
 18. A method according to claim 17,wherein said RLC/MAC unit buffers said LLC PDU messages not carryinghigh priority urgency of transmission profile by generating a LLC PDUborder into the Radio Link Control (RLC) data block.
 19. A methodaccording to claim 17, wherein during transmitting LLC PDU message withSAPI value 7 not carrying high priority urgency of transmission profile,the Radio Link Control/Medium Access Control (RLC/MAC) unit interruptssaid transmission if said RLC/MAC unit receives a new LLC PDU messagewith SAPI value 3 carrying high priority urgency of transmission profileduring said transmission, said RLC/MAC unit buffers said LLC PDU messagewith SAPI value 7 not carrying high priority urgency of transmissionprofile and initiates transmitting said new LLC PDU message with SAPIvalue 3 carrying high priority urgency of transmission profile.
 20. Amethod according to claim 11, wherein a Radio Link Control/Medium AccessControl (RLC/MAC) unit initiates an uplink Temporary Block Flow (TBF)and indicates to a Radio Link Control/Medium Access Control (RLC/MAC) ofthe network if a RLC ACK or a RLC UNACK mode is to be used whentransmitting packet data messages.
 21. A method according to claim 20,wherein Radio Link Control/Medium Access Control (RLC/MAC) of the mobilestation (MS) orders said first packet data message to be delivered inthe RLC UNACK mode and said second packet data to be delivered in theRLC ACK mode.
 22. A method according to claim 9, wherein the step ofreceiving comprises a preliminary step of checking that said firstpacket data messages and said second packet data messages are receivedin-sequence order according to a window number inside a Logical LinkControl (LLC) header of said first packet data message or said secondpacket data message.
 23. A mobile station (MS) for transferring userdata in a wireless packet data network, the mobile station (MS)comprising a transceiver for transmitting and receiving packet datamessages, wherein the mobile station (MS) comprises: a controllerconfigured to generate packet data protocol (PDP) context activationmessages for informing the network about the activation of packet dataprotocol (PDP) contexts for user data transmission, and a layeredtransmission protocol arrangement comprising a certain protocol layerentity as well as higher protocol layer entities, of which said certainprotocol layer entity is configured to receive packet data messagesbelonging to different packet data protocol (PDP) contexts from at leastone upper protocol layer, to reorder packet data messages received fromat least one upper protocol layer according to a relative urgency oftransmission of packet data protocol (PDP) contexts that the packet datamessages belong to, and to deliver packet data messages further fromsaid certain protocol layer in reordered order.
 24. A mobile station(MS) according to claim 23, wherein the controller requests an uplinkTemporary Block Flow (TBF) for transmitting said packet data protocol(PDP) context activation messages.
 25. A mobile station (MS) accordingto claim 24, wherein the controller, during reception, is arranged tocheck that said first packet data messages and said second packet datamessages are received in-sequence order according a connectioninformation of said first packet data message or said second packet datamessage.
 26. A mobile station (MS) according to claim 25, wherein saidfirst packet data message containing first user data is arranged tobelong to said packet data protocol (PDP) context and said second packetdata unit (PDU) message containing second user data is arranged tobelong to said packet data protocol (PDP) context.
 27. A mobile station(MS) according to claim 26, wherein said first and second user datacomprising urgency of transmission profile, wherein the urgency oftransmission profile includes an additional quality of service (QoS)information of the user data, the first packet data message and thesecond packet data message are arranged to be reordered according to theurgency of transmission profile, if the first connection informationdiffers from the second connection information, by first delivering thepacket data unit message comprising higher urgency of transmissionprofile.
 28. A mobile station (MS) according to claim 27, wherein saidfirst and second user data comprising urgency of transmission profile,wherein the urgency of transmission profile includes an additionalquality of service (QoS) information of the user data, the first packetdata unit (PDU) message and the second packet data unit (PDU) messageare arranged to be reordered according to the urgency of transmissionprofile, if the first connection information is equal to the secondconnection information, by first delivering the packet data unit (PDU)message comprising higher urgency of transmission profile using otherconnection information.
 29. A mobile station (MS) according to claim 28,wherein the layered transmission protocol arrangement is arranged tobuffer said second data messages into a packet data transfer queue for aperiod of time said first packet data message transfer is on-going, andto deliver said second packet data messages after said first packet datadelivery is completed.
 30. A mobile station (MS) according to claim 29,wherein the wireless packet data network is arranged to comprise of aGeneral Packet Radio Service (GPRS) network, wherein said first packetdata messages and said second packet data messages are Logical LinkController (LLC) packet data unit (PDU) messages, and where the protocolactivation message is arranged to activate a GPRS Mobility Management(GMM) unit to associate the packet data protocol (PDP) context to saidfirst packet data messages and to said second packet data messages. 31.A mobile station (MS) according to claim 30, wherein a Logical LinkController (LLC) unit is arranged to assign a first Service Access PointIndicator (SAPI) of a GPRS Mobility Management (GMM) unit to beassociated to said first connection information of said first packetdata message, and a second Service Access Point Indicator (SAPI) of aGPRS Mobility Management (GMM) unit to be associated to said secondconnection information of said second packet data message; said firstSAPI value being different than said second SAPI value.
 32. A mobilestation (MS) according to claim 31, wherein said layered transmissionprotocol arrangement is arranged to reorder said first packet datamessage and said second packet data message according to said first SAPIvalue and said second SAPI value.
 33. A mobile station (MS) according toclaim 31, wherein a Radio Link Control/Medium Access Control (RLC/MAC)unit is arranged to reorder said first packet data message and saidsecond packet data message according to said first SAPI value and saidsecond SAPI value.
 34. A mobile station (MS) according to claim 33,wherein a Radio Link Control/Medium Access Control (RLC/MAC) unit isarranged to read a used SAPI value of the Logical Link Controller (LLC)packet data unit (PDU) message from the LLC PDU message.
 35. A mobilestation (MS) according to claim 34, wherein after sending the last LLCPDU message carrying high priority urgency of transmission profile theRadio Link Control/Medium Access Control (RLC/MAC) unit is arranged toinitiate transmitting LLC PDU messages not carrying high priorityurgency of transmission profile.
 36. A mobile station (MS) according toclaim 34, wherein after sending the last LLC PDU message carrying highpriority urgency of transmission profile, the Radio Link Control/MediumAccess Control (RLC/MAC) unit is arranged to start a timer with apredetermined timeout value and after said timeout value, said RLC/MACunit is arranged to initiate transmitting LLC PDU messages not carryinghigh priority urgency of transmission profile if said RLC/MAC unit hasnot received a new LLC PDU message carrying high priority urgency oftransmission profile during said predetermined timeout value.
 37. Amobile station (MS) according to claim 34, wherein during transmittingLLC PDU messages not carrying high priority urgency of transmissionprofile, the Radio Link Control/Medium Access Control (RLC/MAC) unit isarranged to interrupt said transmission if said RLC/MAC unit receives anew LLC PDU message carrying high priority urgency of transmissionprofile during said transmission, and said RLC/MAC unit is arranged toinitiate transmitting said new LLC PDU message carrying high priorityurgency of transmission profile.
 38. A mobile station (MS) according toclaim 37, wherein said RLC/MAC unit is arranged to buffer said LLC PDUmessages not carrying high priority urgency of transmission profile bygenerating a LLC PDU border into the Radio Link Control (RLC) datablock.
 39. A mobile station (MS) according to claim 37, wherein duringtransmitting LLC PDU message with SAPI=7 not carrying high priorityurgency of transmission profile, the Radio Link Control/Medium AccessControl (RLC/MAC) unit is arranged to interrupt said transmission ifsaid RLC/MAC unit receives a new LLC PDU message with SAPI=3 carryinghigh priority urgency of transmission profile during said transmission,said RLC/MAC unit is arranged to buffer said LLC PDU message with SAPI=7not carrying high priority urgency of transmission profile and toinitiate transmitting said new LLC PDU message with SAPI=3 carrying highpriority urgency of transmission profile.
 40. A mobile station (MS)according to claim 31, wherein a Radio Link Control/Medium AccessControl (RLC/MAC) unit is arranged to initiate an uplink Temporary BlockFlow (TBF) and arranged to indicate to a Radio Link Control/MediumAccess Control (RLC/MAC) of the network if a RLC ACK or a RLC UNACK modeis to be used when transmitting packet data messages.
 41. A mobilestation (MS) according to claim 40, wherein Radio Link Control/MediumAccess Control (RLC/MAC) is arranged to order said first packet datamessage to be delivered in the RLC UNACK mode and said second packetdata to be delivered in the RLC ACK mode.
 42. A mobile station (MS)according to claim 29, wherein the controller, during reception, isarranged to check that said first packet data messages and said secondpacket data messages are received in-sequence order according a windownumber inside a Logical Link Control (LLC) header of said first packetdata message or said second packet data message.
 43. A method related toa network element of a wireless network for transferring user databetween a mobile station (MS) and a wireless packet data network, themethod comprising the steps of: at a certain protocol layer, receiving afirst packet data message from an upper protocol layer, which firstpacket data message belongs to a first packet data protocol (PDP)context characterised by certain first connection information, at saidcertain protocol layer, receiving a second packet data message from anupper protocol layer, which second packet data message belongs to asecond packet data protocol (PDP) context characterised by certainsecond connection information, reordering said first packet data messageand said second packet data message at said certain protocol layeraccording to a relative urgency of transmission of said first and secondpacket data protocol (PDP) contexts, and delivering said first packetdata message and said second data message further from said certainprotocol layer in reordered order.
 44. A method according to claim 43,wherein in the steps of receiving said first packet data message andsaid second packet data message precede a step of configuring comprisingfurther step of receiving packet data protocol (PDP) context activationmessages for the activation of packet data protocol (PDP) contexts foruser data transmission.
 45. A method according to claim 44, wherein thesteps of receiving said first packet data message and said second packetdata message comprise a preliminary step of checking that said firstpacket data messages and said second packet data messages are receivedin-sequence order according said connection information of said firstpacket data message or said second packet data message.
 46. A methodaccording to claim 45, wherein the first packet data message containingfirst user data belongs to first packet data protocol (PDP) context, andthe second packet data message containing second user data belongs tosecond packet data protocol (PDP) context.
 47. A method according toclaim 46, wherein said first and second user data comprising urgency oftransmission profile, wherein the urgency of transmission profileincludes an additional quality of service (QoS) information of the userdata, the first packet data message and the second packet data messageare reordered according to the urgency of transmission profile, if thefirst connection information differs from the second connectioninformation, by first delivering the packet data unit message comprisinghigher urgency of transmission profile.
 48. A method according to claim47, wherein said first and second user data comprising urgency oftransmission profile, wherein the urgency of transmission profileincludes an additional quality of service (QoS) information of the userdata, the first packet data unit (PDU) message and the second packetdata unit (PDU) message are reordered according to the urgency oftransmission profile, if the first connection information is equal tothe second connection information, by first delivering the packet dataunit (PDU) message comprising higher urgency of transmission profileusing other connection information.
 49. A method according to claim 48,wherein the method comprises further steps: the step of reorderingfurther comprises buffering said second packet data messages into apacket data transfer queue for a period of time said first packet datamessage transfer is on-going, and the step of delivering furthercomprises delivering said second packet data messages after said firstpacket data message delivery is completed.
 50. A method according toclaim 49, wherein a Logical Link Controller (LLC) unit assigns a firstService Access Point Indicator (SAPI) of a GPRS Mobility Management(GMM) unit to associate said first connection information of said firstpacket data message, and a second Service Access Point Indicator (SAPI)of a GPRS Mobility Management (GMM) unit to associate said secondconnection information of said second packet data message; said firstSAPI value being different than said second SAPI value.
 51. A methodaccording to claim 50, wherein said first packet data message and saidsecond packet data message are reordered according to said first SAPIvalue and said second SAPI value.
 52. A method according to claim 51,wherein a Radio Link Control/Medium Access Control (RLC/MAC) unitreorders said first packet data message and said second packet datamessage according to said first SAPI value and said second SAPI value.53. A method according to claim 52, wherein a Radio Link Control/MediumAccess Control (RLC/MAC) unit reads a used SAPI value of the LogicalLink Controller (LLC) packet data unit (PDU) message from the LLC PDUmessage.
 54. A method according to claim 53, wherein after sending thelast LLC PDU message carrying high priority urgency of transmissionprofile the Radio Link Control/Medium Access Control (RLC/MAC) unitinitiates transmitting LLC PDU messages not carrying high priorityurgency of transmission profile.
 55. A method according to claim 53,wherein after sending the last LLC PDU message carrying high priorityurgency of transmission profile the Radio Link Control/Medium AccessControl (RLC/MAC) unit starts a timer with a predetermined timeout valueand after said timeout value, said RLC/MAC unit initiates transmittingLLC PDU messages not carrying high priority urgency of transmissionprofile if said RLC/MAC unit has not received a new LLC PDU messagecarrying high priority urgency of transmission profile during saidpredetermined timeout value.
 56. A method according to claim 53, whereinduring transmitting LLC PDU messages not carrying high priority urgencyof transmission profile the Radio Link Control/Medium Access Control(RLC/MAC) unit interrupts said transmission if said RLC/MAC unitreceives a new LLC PDU message carrying high priority urgency oftransmission profile during said transmission, and said RLC/MAC unitinitiates transmitting said new LLC PDU message carrying high priorityurgency of transmission profile.
 57. A method according to claim 56,wherein said RLC/MAC unit buffers said LLC PDU messages not carryinghigh priority urgency of transmission profile by generating a LLC PDUborder into the Radio Link Control (RLC) data block.
 58. A methodaccording to claim 56, wherein during transmitting LLC PDU message withSAPI value 7 not carrying high priority urgency of transmission profile,the Radio Link Control/Medium Access Control (RLC/MAC) unit interruptssaid transmission if said RLC/MAC unit receives a new LLC PDU messagewith SAPI value 3 carrying high priority urgency of transmission profileduring said transmission, said RLC/MAC unit buffers said LLC PDU messagewith SAPI value 7 not carrying high priority urgency of transmissionprofile and initiates transmitting said new LLC PDU message with SAPIvalue 3 carrying high priority urgency of transmission profile.
 59. Amethod according to claim 50, wherein a Radio Link Control/Medium AccessControl (RLC/MAC) unit notifies the indication from the mobile station(MS) if a RLC ACK or a RLC UNACK mode is to be used when transmittingpacket data messages.
 60. A method according to claim 59, wherein RadioLink Control/Medium Access Control (RLC/MAC) of the mobile station (MS)orders said first packet data message to be delivered in the RLC UNACKmode and said second packet data to be delivered in the RLC ACK mode.61. A method according to claim 49, wherein the step of transferringcomprises a preliminary step of checking that said first packet datamessages and said second packet data messages are received in-sequenceorder according to a window number inside a Logical Link Control (LLC)header of said first packet data message or said second packet datamessage.
 62. A method according to claim 43, wherein the network elementis one of the following network elements: a Serving General Packet RadioSupport Node (SGSN), a Base Station Controller (BSC), Mobile SwitchingCenter (MSC) and a Packet Control Unit (PCU) comprising a RLC/MAC unit.63. A network element of a wireless network for transferring user databetween a mobile station (MS) and a wireless packet data network,wherein the network element comprises: a controller configured togenerate packet data protocol (PDP) context activation messages forinforming the network about the activation of packet data protocol (PDP)contexts for user data transmission, and a layered transmission protocolarrangement comprising a certain protocol layer entity as well as higherprotocol layer entities, of which said certain protocol layer entity isconfigured to receive packet data messages belonging to different packetdata protocol (PDP) contexts from at least one upper protocol layer, toreorder packet data messages received from at least one upper protocollayer according to a relative urgency of transmission of packet dataprotocol (PDP) contexts that the packet data messages belong to, and todeliver packet data messages further from said certain protocol layer inreordered order.
 64. A network element according to claim 63, whereinthe controller receives an uplink Temporary Block Flow (TBF) forconfiguring said packet data protocol (PDP) context activation messages.65. A network element according to claim 64, wherein the controller,during reception, is arranged to check that said first packet datamessages and said second packet data messages are received in-sequenceorder according a connection information of said first packet datamessage or said second packet data message.
 66. A network elementaccording to claim 65, wherein said first packet data message containingfirst user data is arranged to belong to said packet data protocol (PDP)context and said second packet data unit (PDU) message containing seconduser data is arranged to belong to said packet data protocol (PDP)context.
 67. A network element according to claim 66, wherein said firstand second user data comprising urgency of transmission profile, whereinthe urgency of transmission profile includes an additional quality ofservice (QoS) information of the user data, the first packet datamessage and the second packet data message are arranged to be reorderedaccording to the urgency of transmission profile, if the firstconnection information differs from the second connection information,by first delivering the packet data unit message comprising higherurgency of transmission profile.
 68. A network element according toclaim 67, wherein said first and second user data comprising urgency oftransmission profile, wherein the urgency of transmission profileincludes an additional quality of service (QoS) information of the userdata, the first packet data unit (PDU) message and the second packetdata unit (PDU) message are arranged to be reordered according to theurgency of transmission profile, if the first connection information isequal to the second connection information, by first delivering thepacket data unit (PDU) message comprising higher urgency of transmissionprofile using other connection information.
 69. A network elementaccording to claim 68, wherein said layered transmission protocolarrangement is arranged to buffer said second data messages into apacket data transfer queue for a period of time said first packet datamessage transfer is on-going, and to deliver said second packet datamessages after said first packet data delivery is completed.
 70. Anetwork element according to claim 69, wherein a Logical Link Controller(LLC) unit is arranged to assign a first Service Access Point Indicator(SAPI) of a GPRS Mobility Management (GMM) unit to associate said firstconnection information of said first packet data message, and a secondService Access Point Indicator (SAPI) of a GPRS Mobility Management(GMM) unit to associate said second connection information of saidsecond packet data message; said first SAPI value being different thansaid second SAPI value.
 71. A network element according to claim 70,wherein the layered transmission protocol arrangement is arranged toreorder said first packet data message and said second packet datamessage according to said first SAPI value and said second SAPI value.72. A network element according to claim 71, wherein a Radio LinkControl/Medium Access Control (RLC/MAC) unit is arranged to reorder saidfirst packet data message and said second packet data message accordingto said first SAPI value and said second SAPI value.
 73. A networkelement according to claim 72, wherein a Radio Link Control/MediumAccess Control (RLC/MAC) unit is arranged to read a used SAPI value ofthe Logical Link Controller (LLC) packet data unit (PDU) message fromthe LLC PDU message.
 74. A network element according to claim 73,wherein after sending the last LLC PDU message carrying high priorityurgency of transmission profile the Radio Link Control/Medium AccessControl (RLC/MAC) unit is arranged to initiate transmitting LLC PDUmessages not carrying high priority urgency of transmission profile. 75.A network element according to claim 73, wherein after sending the lastLLC PDU message carrying high priority urgency of transmission profilethe Radio Link Control/Medium Access Control (RLC/MAC) unit is arrangedto start a timer with a predetermined timeout value and after saidtimeout value, said RLC/MAC unit initiates transmitting LLC PDU messagesnot carrying high priority urgency of transmission profile if saidRLC/MAC unit has not received a new LLC PDU message carrying highpriority urgency of transmission profile during said predeterminedtimeout value.
 76. A network element according to claim 73, whereinduring transmitting LLC PDU messages not carrying high priority urgencyof transmission profile the Radio Link Control/Medium Access Control(RLC/MAC) unit is arranged to interrupt said transmission if saidRLC/MAC unit receives a new LLC PDU message carrying high priorityurgency of transmission profile during said transmission, and saidRLC/MAC unit initiates transmitting said new LLC PDU message carryinghigh priority urgency of transmission profile.
 77. A network elementaccording to claim 76, wherein said RLC/MAC unit is arranged to buffersaid LLC PDU messages not carrying high priority urgency of transmissionprofile by generating a LLC PDU border into the Radio Link Control (RLC)data block.
 78. A network element according to claim 76, wherein duringtransmitting LLC PDU message with SAPI value 7 not carrying highpriority urgency of transmission profile, the Radio Link Control/MediumAccess Control (RLC/MAC) unit is arranged to interrupt said transmissionif said RLC/MAC unit receives a new LLC PDU message with SAPI value 3carrying high priority urgency of transmission profile during saidtransmission, said RLC/MAC unit buffers said LLC PDU message with SAPIvalue 7 not carrying high priority urgency of transmission profile andinitiates transmitting said new LLC PDU message with SAPI value 3carrying high priority urgency of transmission profile.
 79. A networkelement according to claim 70, wherein a Radio Link Control/MediumAccess Control (RLC/MAC) unit is arranged to notify the indication fromthe mobile station (MS) if a RLC ACK or a RLC UNACK mode is to be usedwhen transmitting packet data messages.
 80. A network element accordingto claim 79, wherein Radio Link Control/Medium Access Control (RLC/MAC)is arranged to order said first packet data message to be delivered inthe RLC UNACK mode and said second packet data to be delivered in theRLC ACK mode.
 81. A network element according to claim 69, wherein thecontroller, during reception, is arranged to check that said firstpacket data messages and said second packet data messages are receivedin-sequence order according to a window number inside a Logical LinkControl (LLC) header of said first packet data message or said secondpacket data message.
 82. A network element according to claim 63,wherein the network element is arranged to be one of the followingnetwork elements: a Serving General Packet Radio Support Node (SGSN), aBase Station Controller (BSC), Mobile Switching Center (MSC) and aPacket Control Unit (PCU) comprising a RLC/MAC unit.